1. Field
Apparatuses and methods consistent with exemplary embodiments relate to providing a display apparatus and a method of driving backlight thereof, and more particularly, to providing a display apparatus that, if a dimming frequency of the display apparatus is lower than or equal to a preset frequency, reduces a flicker phenomenon, and a method of driving backlight thereof.
2. Description of the Related Art
A liquid crystal display (LCD) is thinner, lighter, and requires a lower driving voltage and lower power consumption than other types of display apparatuses and thus has been widely used. However, the LCD is a nonluminous device that does not emit light and thus requires an additional backlight unit for supplying light to a liquid crystal panel.
However, if the LCD displays consecutive frames, a section in which frames overlap each other is generated, and thus an afterimage is left. A method of dimming a light-emitting diode (LED) is used to solve this problem of the afterimage. In other words, an operation of turning on the LED for a preset time and an operation of turning off the LED for a preset time are alternately repeated to prevent a phenomenon in which an afterimage of a frame is left.
Specifically, a dimming method of an LED is classified into an analog dimming method and a digital dimming method. The analog dimming method refers to a method of adjusting an amount of current supplied to the LED to adjust brightness of the LED. A pulse width modulation (PWM) dimming method which is one of digital dimming methods refers to a method of adjusting a ratio between on and off times of the LED to adjust the brightness of the LED. For example, if a PWM signal in which a ratio between on and off times is 4:1 is provided to the LED, the brightness of the LED may be about 80% of maximum brightness.
If a basic dimming frequency is lower than or equal to a preset frequency (for example, 60 Hz), duration of each of the LED being turned on and turned off becomes longer. Therefore, there may occur a flicker phenomenon in which a user visually feels periodic changes of light intensity such as flickering of a screen. As a result, there is a need for a technology for mitigating such a flicker phenomenon.